我再次问这个问题的唯一原因是因为我尝试了所有答案，但它对我不起作用，我正在尝试获取当前用户位置，但它不起作用，所以这就是我一直在尝试做的事情，顺便说一句，我已经设置了所有权限，并且我一直在空对象引用错误和致命执行上获得双 android location.getT纬度 主要， 请帮助我这是我的GPSTRACKER Java类代码：
package com.example.nefissa.androidtest;
import android.*;
import android.Manifest;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.support.v4.content.ContextCompat;
public class GPSTracker extends Service implements LocationListener{
private final Context context;
boolean isGPSEnabled =false;
boolean isNetworkEnabled =false;
boolean canGetLocation =false;
Location location;
protected LocationManager locationManager;
public GPSTracker(Context context){
this.context=context;
}
// create a GetLocation Method //
public Location getLocation(){
try{
locationManager=(LocationManager) context.getSystemService(LOCATION_SERVICE);
isGPSEnabled = locationManager.isProviderEnabled(locationManager.GPS_PROVIDER);
isNetworkEnabled=locationManager.isProviderEnabled(locationManager.NETWORK_PROVIDER);
if(ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
|| ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED ){
if(isGPSEnabled){
if(location==null){
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,100000,10,this);
if(locationManager!=null){
location=locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
}
}
}
// if location is not found from GPS then it will found from network //
if(location==null){
if(isNetworkEnabled){
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,100000,10,this);
if(locationManager!=null){
location=locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
}
}
}
}
}catch(Exception e){
}
return location;
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
}
和我的主要活动代码：
package com.example.nefissa.androidtest;
import android.location.Location;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
private GPSTracker gpsTracker;
private Location mLocation;
double latitude;
double longitude;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
gpsTracker= new GPSTracker(getApplicationContext());
mLocation=gpsTracker.getLocation();
latitude= mLocation.getLatitude();
longitude= mLocation.getLongitude();
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Add a marker in Sydney and move the camera
LatLng sydney = new LatLng(latitude,longitude);
mMap.addMarker(new MarkerOptions().position(sydney).title("you are here"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
}
调用 onMapReady 后，最好初始化 gpsTracker。
gpsTracker= new GPSTracker(getApplicationContext());
if(gpsTracker!=null){
mLocation=gpsTracker.getLocation();
latitude= mLocation.getLatitude();
longitude= mLocation.getLongitude();
}
我认为gpsTracker.getLocation必须改为逻辑。请阅读安卓GPS指南。
尝试使用
全球定位系统追踪
器public GPSTracker(Activity activity) {
this.mActivity = activity;
getLocation();
}
public void getLocation() {
try {
locationManager = (LocationManager) mActivity
.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled || !isNetworkEnabled) {
showSettingsAlert();
} else {
this.canGetLocation = true;
if (isNetworkEnabled) {
if (ActivityCompat.checkSelfPermission(mActivity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(mActivity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(mActivity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, 1);
} else {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* Function to get latitude
*/
public double getLatitude() {
if (location != null) {
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
*/
public double getLongitude() {
if (location != null) {
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to ic_check GPS/wifi enabled
*
* @return boolean
*/
public boolean canGetLocation() {
return this.canGetLocation;
}
也来自活动调用
创建
//
gps = new GPSTracker(SignUpActivity.this);
if (gps.canGetLocation) {
lat = String.valueOf(gps.getLatitude());
lng = String.valueOf(gps.getLongitude());
}
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